acid vs back breaker

acid

noun
  • A sour substance. 

  • LSD, lysergic acid diethylamide. 

  • Any compound which yields H+ ions (protons) when dissolved in water; an Arrhenius acid. 

  • Any compound that easily donates protons to a base; a Brønsted acid. 

  • Any compound that can accept a pair of electrons to form a covalent bond; a Lewis acid. 

  • Any corrosive substance. 

adj
  • Sour, sharp, or biting to the taste; tart; having the taste of vinegar. 

  • Sour-tempered. 

  • Of or pertaining to an acid; acidic. 

  • Denoting a musical genre that is a distortion (as if hallucinogenic) of an existing genre, as in acid house, acid jazz, acid rock. 

back breaker

How often have the words acid and back breaker occurred in a corpus of books? (source: Google Ngram Viewer )